The objectives of this research are to propose an efficient and proper model that fits the cassava and rubber yields data. A generalized estimating equation (GEE) and a linear mixed model (LMM) with spatial correlation following the conditional autoregressive model (CAR) were adopted. The dependent variables are the cassava and rubber yields collected each month in every province of Thailand. The factors considered are rainfall averaged temperatures and regions. The results from GEE and LMM show that the factors influencing on the cassava and rubber yields are rainfall averaged temperature and region. Both GEE and LMM fit the correlated data. The GEE is used to explain the influence of factors on the yields in all provinces while the LMM is used to explain the influence of factors on the yields in each province.

The purpose of the qualitative study was to seek for on guidelines for increasing productivity of organic products (vegetables) of Thamsua community members in Kaeng Krachan Phetchaburi Province. Data collection was done through observation interview and document analysis. The samples were 10 leaders and members of Organic Product Division of Thamsua Community in Kaeng Krachan Phetchaburi. The research results revealed that problems and obstacles in increasing the organic product were the lack of worker and continuity to produce goods for distributing to meet the market demand. The solution could be done by increasingly distributing products the surrounding communities to meet the needs and quality control standard of the market. In terms of the management the community should have a clear management plan and appoint a committee to co-ordinate its policies plans regulations and management. They could invite other members from neighboring communities to be involved. As for the solutions for the production and product diversification external agencies might be asked to participate in the productivity enhancement such as public or private sectors and educational institutions for example. The government might be in charge of supporting for career development and income private sectors for more marketing channels while educational institutions might support for knowledge needed for increasing the productivity. Concerning marketing solutions for more distribution channels online marketing should be set up by coordinating with private sectors to provide additional distribution channels such as organizing product display booths with public and private sectors. Financial and accounting solutions for the lack of management funding sources should be organized through the community savings such as the Cooperative Community Enterprise or Provincial Cooperative office to e involved in accounting management to create systematic financial management.

This research focuses on the production of charcoal briquettes from agricultural residues by using durian and nypa palm peel mixtures. The objectives of this study are to study the combustion efficiency of charcoal briquettes; study the suitable ratio for the production of briquettes with the ratios of durian : nypa palm peel mixtures as 100:0 50:50 25:75 and 0:100; recycle the agricultural residues as the renewable energy sources and analyze the fuel characteristics; moisture content ash content volatile matters fixed carbon and heating value. The results showed that the best ratio for the combustion efficiency of charcoal briquettes is 50:50 with the minimum moisture content of 4.68% the minimum ash content of 2.70% the volatile matters of 10.33% ; the maximum fixed carbon of 25.56% and all characteristics are met with the standard of charcoal briquettes from the local community products. In the ratio of 100:0 it showed the maximum heating value as 5399 calories per gram. Therefore the 50:50 charcoal briquettes are suitable as the renewable energy source. Besides the capacity of odor adsorption was analyzed by adding the odor substances (mothball) in two bottles with three mothballs for each bottle for two consecutive days before removal. Then sic of 50:50 charcoal briquettes were added into one bottle. Ten testers smelled the bottle every two days for six days. The result showed that the bottle with the charcoal briquettes had odor less than the bottle without briquettes. Hence the charcoal briquettes from durian and nyla palm peel mixtures have the best odor adsorption capacity and are suitable for household uses.

The research is to present the biogas production from rice straws with anaerobic digester. Firstly three digester tanks contain dry rice straw 3 kg slice with length 1-2 inch and water 60 lite. Digester A was a control sample. Digester B was designed for minimum performance (add the morass 2 lite) while the digester C was designed for Carbon/Nitrogen control (add urea 1 kg.). The biogas was operated for 30 days and measured which highest percent of Lower Explosive Limit was 93%. This studied show the simple methods to producing the biogas from the rice straw.